Morita et al.
mmol) was placed in a 100-mL Schlenk tube and dissolved with
THF (22 mL). After the solution was cooled at -78 °C, n-BuLi
(1.6 M hexane solution, 0.63 mL, 1.0 mmol) was added and the
mixture was stirred at -78 °C for 1 h. To this mixture was added
tributyltin(IV) chloride (0.29 mL, 1.0 mmol), and the solution was
gradually warmed to room temperature. After being stirred for 30
min, a pH 7.0 phosphate buffer solution (0.1 M, 25 mL) was poured,
and the reaction mixture was extracted with ethyl acetate (2 × 30
mL). The combined organic extracts were dried over anhydrous
Na2SO4, then filtered and concentrated under reduced pressure to
give the mixture of tributyltin-substituted EDT-TTF (written simply
as EDT-TTF-SnBu3) and EDT-TTF (766 mg) as a red oil. This
crude oil was used for the next coupling reactions.
The mixture of EDT-TTF-SnBu3 and EDT-TTF (766 mg), 4a
(404 mg, 1.0 mmol), copper(I) iodide (58 mg, 0.30 mmol), and
tris(o-tolyl)phosphine (96 mg, 0.30 mmol) were placed in a 50-
mL Schlenk tube and dissolved in THF (15 mL). To this mixture
was added tetrakis(triphenylphosphine)palladium(0) (117 mg, 0.10
mmol), and the solution was stirred at room temperature for 27 h.
After quenching by the addition of water (30 mL), the solution
was extracted with ethyl acetate (2 × 40 mL). The combined
organic extracts were dried over anhydrous Na2SO4, then filtered
and concentrated under reduced pressure. The residual powder was
purified by silica gel column chromatography with 5:1 hexanes-
ethyl acetate and ethyl acetate, to give a mixture of the EDT-TTF
derivative with benzoyl-protected butyluracil 5a and 4a (516 mg).
5a: TLC Rf 0.58 (1:1 hexane/ethyl acetate).
type complementary double N-H‚‚‚O H-bonds in all EDT-TTF
derivatives independent of substituent on uracil and the redox
nature of the molecule. Construction of multidimensional
networks through noncovalent interactions and achievement of
high electric conductivity in the H-bonded CT complex will
bring us the beginning of the elucidation and realization of the
cooperative proton and electron-transfer process.25
Experimental Section26
5-Iodo-N1-phenyluracil (3b). N1-Phenyluracil10 (2.5 g, 13 mmol)
was placed in a Schlenk tube equipped with a reflux condenser
and dissolved with CH2Cl2 (15 mL). To this mixture was added
iodine chloride (1.4 mL, 27 mmol) and the mixture was refluxed
for 1 h. After the solution was cooled at room temperature, the
resulting white precipitate was collected by filtration and washed
with ether. This residue was recrystallized from ethyl acetate-
ethanol (1:1) to give 5-iodo-N1-phenyluracil (3.3 g, 77%) as a white
solid: mp 285-286 °C; TLC Rf 0.64 (ethyl acetate); 1H NMR (270
MHz, DMSO-d6) δ 7.44 (m, 5H), 8.18 (s, 1H), 11.8 (br s, 1H); IR
(KBr) 3165, 3050, 1701, 1675 cm-1; EI-MS, m/z 314 (M+, 47%).
Anal. Calcd for C10H7N2O2I: C, 38.24; H, 2.25; N, 8.92. Found:
C, 37.97; H, 2.17; N, 8.83.
N3-Benzoyl-N1-n-butyl-5-iodouracil (4a). N1-n-Butyl-5-iodor-
acil6 (5.0 g, 17 mmol) was placed in a 100-mL round-bottomed
flask and dissolved in CH3CN (17 mL) and pyridine (7 mL)
following addition of benzoyl chloride (4.3 mL, 37 mmol) at room
temperature. After the solution was stirred at room temperature for
24 h, the solvents were removed by evaporation, and ethyl acetate
(300 mL) and water (100 m) were added. The organic layer was
separated and washed with water (100 mL), dried over anhydrous
Na2SO4, filtered, and concentrated under reduced pressure. The
residual yellow oil was recrystallized from hexanes-ethyl acetate
to give 4a (6.5 g, 96%) as a white solid. Mp 129-130 °C; TLC Rf
0.63 (1:1 hexane/ethyl acetate); 1H NMR (270 MHz, DMSO-d6) δ
0.88 (t, 3, J ) 7.3 Hz), 1.21-1.35 (m, 2), 1.55-1.66 (m, 2), 3.73
(t, 2, J ) 7.4 Hz), 7.56-7.62 (m, 2), 7.75-7.81 (m, 1), 7.95-7.99
(m, 2), 8.45 (s, 1); IR (KBr) 3074, 1743, 1694, 1662 cm-1; FAB-
MS, m/z 399 (M + H+). Anal. Calcd for C15H15N2O3I: C, 45.24;
H, 3.80; N, 7.04. Found: C, 45.24; H, 3.62; N, 7.11.
The mixture of 5a and 4a (516 mg) was placed in a 20-mL
Schlenk tube, dispersed in 30% methylamine methanol solution (6
mL), and stirred at room temperature for 30 min. After being cooled
at 0 °C, the solution was neutralized by concentrated acetic acid
and collected, to give 1a (137 mg) as a reddish orange powder in
29% yield in three steps from EDT-TTF. Mp 240-241 °C dec;
1
TLC Rf 0.60 (ethyl acetate); H NMR (270 MHz, DMSO-d6) δ
0.90 (t, 3, J ) 7.3 Hz), 1.21-1.32 (m, 2), 1.52-1.63 (m, 2), 3.40
(s, 4), 3.73 (t, 2, J ) 7.1 Hz), 7.34 (s, 1), 7.87 (s, 1), 11.6 (br s, 1);
IR (KBr) 3415, 2954, 1703, 1661 cm-1; UV (KBr) 308, 416 nm;
EI-MS m/z 460 (M+, 71%). Anal. Calcd for C16H16N2O2S6: C,
41.71; H, 3.50; N, 6.08. Found: C, 41.59; H, 3.42; N, 5.97.
2-{4-(N1’-Phenyluracil-5’-yl)-1,3-dithile-2-ylidene}-5,6-dihy-
dro-1,3-dithiolo[4,5-b][1,4]dithiin (1b). EDT-TTF27 (100 mg, 0.34
mmol) was placed in a 100-mL Schlenk tube and dissolved in THF
(8 mL). After the mixture was cooled at -78 °C, n-BuLi (1.6 M
hexane solution, 0.21 mL, 0.34 mmol) was added and the solution
was at -78 °C for 1 h. To this mixture was added tributyltin(IV)
chloride (0.09 mL, 0.34 mmol), and the solution was gradually
warmed to room temperature. After the solution was stirred for 30
min, a pH 7.0 phosphate buffer solution (0.1 M, 15 mL) was added,
and the reaction mixture was extracted with ethyl acetate (2 × 30
mL). The combined organic extracts were dried over anhydrous
Na2SO4, then filtered and concentrated under reduced pressure, to
give a mixture of EDT-TTF-SnBu3 and EDT-TTF (255 mg) as a
red oil. This crude oil was used for the next coupling reactions.
The mixture of EDT-TTF-SnBu3 and EDT-TTF (255 mg), 4b
(141 mg, 0.34 mmol), copper(I) iodide (19 mg, 0.10 mmol), and
tris(o-tolyl)phosphine (32 mg, 0.10 mmol) were placed in a 20-
mL Schlenk tube and dissolved with THF (5 mL). To this mixture
was added tetrakis(triphenylphosphine)palladium(0) (39 mg, 0.034
mmol), and the solution was stirred at room temperature for 22 h.
After quenching by the addition of water (20 mL), the solution
was extracted with ethyl acetate (2 × 30 mL). The combined
organic extracts were dried over anhydrous Na2SO4, then filtered
and concentrated under reduced pressure. The residual powder was
purified by silica gel column chromatography with 5:1 hexanes-
ethyl acetate and ethyl acetate, to give the mixture of EDT-TTF
derivative with benzoyl-protected phenyluracil 5b and 4b (165 mg).
5b: TLC Rf 0.63 (1:1 hexane/ethyl acetate).
N3-Benzoyl-N1-phenyl-5-iodouracil (4b). 5-Iodo-N1-phenylu-
racil (5.1 g, 16 mmol) was placed in a 100-mL round-bottomed
flask and dissolved in CH3CN (20 mL) and pyridine (7 mL)
following addition of benzoyl chloride (4.2 mL, 36 mmol) at room
temperature. After being stirred at room temperature for 24 h, the
solvents were removed by evaporation and ethyl acetate (300 mL)
and water (100 m) were added. The organic layer was separated
and washed with water (100 mL) and dried over anhydrous Na2-
SO4, filtered, and concentrated under reduced pressure. The residual
white solid was recrystallized from hexanes-ethyl acetate, to give
4b (4.8 g, 69%) as a white solid. Mp 216-218 °C; TLC Rf 0.63
(1:1 hexane/ethyl acetate); 1H NMR (270 MHz, DMSO-d6) δ 7.35-
7.42 (m, 2), 7.44-7.54 (m, 5), 7.63-7.69 (m, 1), 7.91 (s, 1), 7.94-
7.99 (m, 2); IR (KBr) 3075, 1743, 1695, 1666 cm-1; FAB-MS,
m/z 419 (M+ + H). Anal. Calcd for C17H11N2O3I: C, 48.83; H,
2.65; N, 6.70. Found: C, 49.09; H, 2.56; N, 6.69.
2-{4-(N1’-n-Butyluracil-5’-yl)-1,3-dithile-2-ylidene}-5,6-dihy-
dro-1,3-dithiolo[4,5-b][1,4]dithiin (1a). EDT-TTF27 (300 mg, 1.0
(25) Nakasuji, K.; Sugiura, K.; Kitagawa, T.; Toyoda, J.; Okamoto, H.;
Okaniwa, K.; Mitani, T.; Yamamoto, H.; Murata, I.; Kawamoto, A.; Tanaka,
J. J. Am. Chem. Soc. 1991, 113, 1862-1864.
(26) See the Experimental Section in the Supporting Information for
X-ray crystal structure analyses.
(27) (a) Papavassiliou, G. C.; Mousdis, G. A.; Yiannopoulos, S. Y.;
Kakoussis, V. C.; Zambounnis, J. S. Synth. Met. 1998, 27, B373. (b)
Papavassilou, G. C.; Kakoussis, V. C.; Mousdis, G. A.; Gionis, V.;
Yiannnopoulos, S. Y. Mol. Cryst. Liq. Cryst. Incorporating Nonlinear Opt.
1998, 156, 269.
The mixture of 5b and 4b (165 mg) was placed in a 20-mL
Schlenk tube, dispersed in 30% methylamine methanol solution (2
5636 J. Org. Chem., Vol. 71, No. 15, 2006